Connection to servers only works on second attempt

Question

Since two weeks i'm having problems connection to the local servers in our company network.

Using RDP to connect to any server fails on the first attempt. If i attempt it again right after the "failed" message, it works. If i wait a few minutes, the connection attempt will fail again.

The .NET application i'm working on has problems establishing a SQL Connection to the remote SQL Servers. Again, if i attempt it multiple times in short period it works.

The problem is really frustrating, since it takes ages to run anything from my development PC, cause i have to restart the applications over and over again.

This problem however only appears to exist on my PC. My colleagues have zero problems and our admins cannot reproduce the problem or have any clue whats wrong. Before i reinstall my PC and waste 1-2 days putting everything back on, i wanted to ask here if anyone got an idea what the problem might be.

Firewalls (serverside and on my PC) are turned off. I'm running Windows 10. Ping works just fine. SQL Management Studio also works perfectly, while the .NET applications (using EntityFramework and ADO.Net) have problems.

Answer 1

That's pretty old problem...

Try this:

WinKey+R and run

rundll32.exe keymgr.dll,KRShowKeyMgr

and delete saved RDP credentials then logoff and re-login again.

When you will try to connect next time over RDP use "correct" username. If you connecting to domain then it should be domain\user and avoid domain (use just username) if you connecting to computer that isn't member of domain.

If you're owner of Windows 10 Pro, you can use procedure described here

I will cite most important steps here:

Run gpedit.msc and navigate to:

Computer Configuration
Administrative template
System
Credential Delegation
Allow Saved Credentials with NTLM-only Server Authentication
Enable (Show: TERMSRV/*)

To apply new settings - re-login or at command prompt, run gpupdate